?url_ver=Z39.88-2004&rft_id=10.4028%2Fwww.scientific.net%2FJERA.13.1&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aufirst=H.&rft.aulast=Gasim&rft.au=Gasim%2C+H.&rft.volume=13&rft.issn=16633571&rft.atitle=Treatment+of+petroleum+refinery+wastewater+using+extended+aeration+activated+sludge&rft.pages=1-7&rft.title=International+Journal+of+Engineering+Research+in+Africa&rft.date=2015&rft.genre=article